I have been lazy this past year (since my new gym has much more in the way of machines). All I ever did was BOR. This past year, I used a lot of machines that support the chest while you row.

A month ago I switched back to good old barbell rows. It is my opinion that for overall back development and stimulation, BOR are FAR superior. You have so many options you can control. Back angle, even slight cheating...etc. Muscle recruitment is far higher. I dont think you will go backwards using machines, but you are losing out on many of the stabilizer muscles that come into play with a BOR. They are now back to the main exercise I build my back around where they belong. Hammer rows are relegated back to "icing on the cake"